SEG3101 (Fall 2010)
Requirements Specification with
the IEEE 830 Standard
DRAFT
Gregor v. Bochmann, University of Ottawa
Based on Powerpoint slides by Gunter Mussbacher (2009)
with material from:
IEEE 830-1998 Standard,
Daniel Amyot 2008, Stéphane Somé 2008
Table of Contents
• Requirements Specification Document
• IEEE 830 Standard
• Relationship of IEEE 830 and ISO/IEC 12207
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SEG3101 (Fall 2009). Requirements Specification with the IEEE 830 Standard. © 2009 Gunter Mussbacher
Requirements Specification Document
IEEE 830 Standard
Relationship of IEEE 830 and ISO/IEC 12207
Requirements Specification Document (1)
• Clearly and accurately describes each of the essential
requirements (functions, performance, design constraints,
and quality attributes) of the system / software and its
external interfaces
• Defines the scope and boundaries of the system / software
• Each requirement must be described in such a way that it is
feasible and objectively verifiable by a prescribed method
(e.g., by inspection, demonstration, analysis, or test)
• Basis for contractual agreements between contractors or
suppliers and customers
• Elaborated from elicitation notes
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SEG3101 (Fall 2009). Requirements Specification with the IEEE 830 Standard. © 2009 Gunter Mussbacher
Requirements Specification Document
IEEE 830 Standard
Relationship of IEEE 830 and ISO/IEC 12207
Requirements Specification Document (2)
• Specifications are intended to a diverse audience
• Customers and users for validation, contract, ...
• Systems (requirements) analysts
• Developers, programmers to implement the system
• Testers to check that the requirements have been met
• Project Managers to measure and control the project
• Different levels of detail and formality is needed for each
audience
• Different templates for requirements specifications
• e.g. IEEE 830
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SEG3101 (Fall 2009). Requirements Specification with the IEEE 830 Standard. © 2009 Gunter Mussbacher
Requirements Specification Document
IEEE 830 Standard
Relationship of IEEE 830 and ISO/IEC 12207
Example Specification (1)
lamp
Appearance
12 cm
switch
lever
Causal
relationship
Input
Timing
relationship
Output
• When the switch lever is moved down, then, within 0.1
seconds, the lamp illuminates.
• When the switch lever is moved up, then, within 0.2 seconds,
the lamp goes out.
Source: Bray 2004
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SEG3101 (Fall 2009). Requirements Specification with the IEEE 830 Standard. © 2009 Gunter Mussbacher
Requirements Specification Document
IEEE 830 Standard
Relationship of IEEE 830 and ISO/IEC 12207
Example Specification (2)
• Extract from the requirements specification
• R1: The system shall provide illumination of at least 500 candela.
• R2: The system shall fit within a cube with maximum width of 15cm.
• R3: The illumination can be switched on and off by a human operator.
• R4: The system shall respond to operator input within 0.5 seconds.
• R5: The system shall have a built-in power supply which should be
capable of maintaining continuous illumination for at least 4 hours.
• etc . . . . . . .
• Several alternative designs could satisfy these requirements
Source: Bray 2004
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SEG3101 (Fall 2009). Requirements Specification with the IEEE 830 Standard. © 2009 Gunter Mussbacher
Requirements Specification Document
IEEE 830 Standard
Relationship of IEEE 830 and ISO/IEC 12207
IEEE 830-1998 Standard
• Title of Standard
• « IEEE Recommended Practice for Software Requirements
Specifications »
• Describes the content and qualities of a good software
requirements specification (SRS)
• Presents several sample SRS outlines
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SEG3101 (Fall 2009). Requirements Specification with the IEEE 830 Standard. © 2009 Gunter Mussbacher
Requirements Specification Document
IEEE 830 Standard
Relationship of IEEE 830 and ISO/IEC 12207
IEEE 830-1998 Standard – Objectives
• Help software customers to accurately describe what they
wish to obtain
• Help software suppliers to understand exactly what the
customer wants
• Help participants to:
• Develop a template (format and content) for the software requirements
specification (SRS) in their own organizations
• Develop additional documents such as SRS quality checklists or an
SRS writer’s handbook
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SEG3101 (Fall 2009). Requirements Specification with the IEEE 830 Standard. © 2009 Gunter Mussbacher
Requirements Specification Document
IEEE 830 Standard
Relationship of IEEE 830 and ISO/IEC 12207
IEEE 830-1998 Standard – Benefits
• Establish the basis for agreement between the customers
and the suppliers on what the software product is to do
• Reduce the development effort
• Forced to consider requirements early  reduces later redesign,
recoding, retesting
• Provide a basis for realistic estimates of costs and schedules
• Provide a basis for validation and verification
• Facilitate transfer of the software product to new users or new
machines
• Serve as a basis for enhancement requests
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SEG3101 (Fall 2009). Requirements Specification with the IEEE 830 Standard. © 2009 Gunter Mussbacher
Requirements Specification Document
IEEE 830 Standard
Relationship of IEEE 830 and ISO/IEC 12207
IEEE 830-1998 Standard – Considerations
• Section 4 of IEEE 830 (how to produce a good SRS)
• Nature (goals) of SRS
• Functionality, interfaces, performance, qualities, design constraints
• Environment of the SRS
• Where does it fit in the overall project hierarchy
• Characteristics of a good SRS
• Generalization of the characteristics of good requirements to the document
• Evolution of the SRS
• Implies a change management process
• Prototyping
• Helps elicit software requirements and reach closure on the SRS
• Including design and project requirements in the SRS
• Focus on external behavior and the product, not the design and the
production process (describe in a separate document)
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SEG3101 (Fall 2009). Requirements Specification with the IEEE 830 Standard. © 2009 Gunter Mussbacher
Requirements Specification Document
IEEE 830 Standard
Relationship of IEEE 830 and ISO/IEC 12207
IEEE 830-1998 Standard – Structure of the SRS
• Section 5 of IEEE 830
• Contents of SRS
• Introduction
• General description of the software product
• Specific requirements (detailed)
• Additional information such as appendixes and index, if necessary
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SEG3101 (Fall 2009). Requirements Specification with the IEEE 830 Standard. © 2009 Gunter Mussbacher
Requirements Specification Document
IEEE 830 Standard
Relationship of IEEE 830 and ISO/IEC 12207
IEEE 830-1998 Standard – Section 1 of SRS
• Title
• Table of Contents
• 1. Introduction
• 1.1 Purpose
•Describe purpose of this SRS
•Describe intended audience
•Identify the software product
•Enumerate what the system will and will not do
•Describe user classes and benefits for each
• 1.2 Scope
• 1.3 Definitions. Acronyms, and Abbreviations
• 1.4 References
• 1.5 Overview
• 2. Overall Description
• 3. Specific Requirements
• Appendices
• Index
•Define the vocabulary of the SRS
(may reference appendix)
•List all referenced documents including sources
(e.g., Use Case Model and Problem Statement;
Experts in the field)
•Describe the content of the rest of the SRS
•Describe how the SRS is organized
SEG3101 (Fall 2009). Requirements Specification with the IEEE 830 Standard. © 2009 Gunter Mussbacher
Requirements Specification Document
IEEE 830 Standard
Relationship of IEEE 830 and ISO/IEC 12207
IEEE 830-1998 Standard – Section 2 of SRS
• Title
• Table of Contents
• 1. Introduction
• 2. Overall Description
•Present the business case and operational concept of the system
•Describe how the proposed system fits into the business context
•Describe external interfaces: system, user, hardware, software, communication
•Describe constraints: memory, operational, site adaptation
• 2.1 Product Perspective
•Summarize the major functional capabilities
•Include the Use Case Diagram and supporting narrative
(identify actors and use cases)
•Include Data Flow Diagram if appropriate
• 2.2 Product Functions
•Describe and justify technical skills
and capabilities of each user class
• 2.3 User Characteristics
• 2.4 Constraints
• 2.5 Assumptions and Dependencies
• 3. Specific Requirements
• 4. Appendices
• 5. Index
•Describe other constraints that will limit developer’s
options; e.g., regulatory policies; target platform,
database, network software and protocols, development
standards requirements
SEG3101 (Fall 2009). Requirements Specification with the IEEE 830 Standard. © 2009 Gunter Mussbacher
Requirements Specification Document
IEEE 830 Standard
Relationship of IEEE 830 and ISO/IEC 12207
IEEE 830-1998 Standard – Section 3 of SRS (1)
•…
• 1. Introduction
• 2. Overall Description
• 3. Specific Requirements
• 3.1 External Interfaces
• 3.2 Functions
• 3.3 Performance Requirements
Specify software requirements in sufficient
detail to enable designers to design a system to satisfy
those requirements and testers to verify
requirements
State requirements that are externally perceivable by
users, operators, or externally connected systems
Requirements should include, at a minimum, a
description of every input (stimulus) into the system,
every output (response) from the system, and all
functions performed by the system in response to an
input or in support of an output
• 3.4 Logical Database Requirements
(a) Requirements should have characteristics of
• 3.5 Design Constraints
high quality requirements
(b) Requirements should be cross-referenced to
their source.
(c) Requirements should be uniquely identifiable
(d) Requirements should be organized to
maximize readability
• 3.6 Software System Quality Attributes
• 3.7 Object Oriented Models
• 4. Appendices
• 5. Index
SEG3101 (Fall 2009). Requirements Specification with the IEEE 830 Standard. © 2009 Gunter Mussbacher
Requirements Specification Document
IEEE 830 Standard
Relationship of IEEE 830 and ISO/IEC 12207
IEEE 830-1998 Standard – Section 3 of SRS (2)
•…
• 1. Introduction
• 2. Overall Description
• 3. Specific Requirements
•Detail all inputs and outputs
(complement, not duplicate, information presented in section 2)
•Examples: GUI screens, file formats
•Include detailed specifications of each
use case, including collaboration and
other diagrams useful for this purpose
• 3.1 External Interfaces
• 3.2 Functions
• 3.3 Performance Requirements
• 3.4 Logical Database Requirements
• 3.5 Design Constraints
• 3.6 Software System Quality Attributes
• 3.7 Object Oriented Models
• 4. Appendices
• 5. Index
•Include:
a) Types of information used
b) Data entities and their relationships
•Should include:
a) Standards compliance
b) Accounting & Auditing procedures
•The main body of requirements organized in a variety of
possible ways:
a) Architecture Specification
b) Class Diagram
c) State and Collaboration Diagrams
d) Activity Diagram (concurrent/distributed)
SEG3101 (Fall 2009). Requirements Specification with the IEEE 830 Standard. © 2009 Gunter Mussbacher
Requirements Specification Document
IEEE 830 Standard
Relationship of IEEE 830 and ISO/IEC 12207
IEEE 830-1998 Standard – Templates
• Annex A of IEEE 830
• Section 3 (Specific Requirements) may be organized in many
different ways based on
• Modes
• User classes
• Concepts (object/class)
• Features
• Stimuli
• Organizations
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SEG3101 (Fall 2009). Requirements Specification with the IEEE 830 Standard. © 2009 Gunter Mussbacher
Requirements Specification Document
IEEE 830 Standard
Relationship of IEEE 830 and ISO/IEC 12207
Relationship of IEEE 830 and ISO/IEC 12207 (1)
• 12207
• Common framework for « Software life cycle processes »
• ISO/IEC 12207 = IEEE/EIA 12207
• IEEE 830-1998 and IEEE/EIA 12207.1-1997 both place
requirements on documents describing software
requirements
• Annex B of IEEE 830 explains the relationship between the
two sets of requirements for those who want to produce
documents that comply with both standards simultaneously
• Such compliance may be required by customers when
requesting proposals or issuing call for tenders
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SEG3101 (Fall 2009). Requirements Specification with the IEEE 830 Standard. © 2009 Gunter Mussbacher
Requirements Specification Document
IEEE 830 Standard
Relationship of IEEE 830 and ISO/IEC 12207
Relationship of IEEE 830 and ISO/IEC 12207 (1)
• Note: Table B.3 is more detailed and shows the
correspondence between the two standards at the level of
requirements types
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SEG3101 (Fall 2009). Requirements Specification with the IEEE 830 Standard. © 2009 Gunter Mussbacher